Water proofing a conditioned crawl space
We are building a home in Redmond WA that will have a conditioned crawl space with a heavy duty plastic membrane on smoothed grade sealed to the bottom of the walls with pressure treated cleats with spray foam then overlapping the cleats, onto the cement and all the sway up to seal the rim joist. We will have properly designed footing drains that drain to daylight at the back of the property. We are planning to use drainage matrix on the exterior and good draining back fill. Do we need to waterproof the exterior of the foundation walls before applying the drainage matrix? My concern is if we do that the walls will have no way to dry.
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Replies
Will any of your crawl space be below grade?
Be sure to also slope the soil around your house to drain away from the home and provide proper gutters and downspouts to direct water away from the home.
Are there any special conditions with the location or design of your home that would warrant waterproofing the exterior of the crawl space?
Are we talking waterproofing or damp proofing? The IRC defines them differently and has different applications for each. https://codes.iccsafe.org/content/IRC2021P2/chapter-4-foundations#IRC2021P2_Pt03_Ch04_SecR406
Some is below grade. We will be directing surface water away from structure and have a full gutter system draining to daylight also. And we are talking about damp proofing . I am not concerned about hydrostatic pressure just a high water table(footing drains will handle) and dealing with any surface water that does drain down along the walls and generally damp soil for much of the year.